Technical Reports

Start Time Variability and Predictability in Railroad Train and Engine Freight and Passenger Service Employees

  • 03
  • Apr
  • 2014
AUTHOR: Thomas G. Raslear
SUBJECT: Human Factors, Work Schedule & Sleep Patterns
KEYWORDS: Work schedules, start time variability, fatigue, train and engine service, accident probability, FAST
ABSTRACT: Start time variability in work schedules is often hypothesized to be a cause of railroad employee fatigue because unpredictable work start times prevent employees from planning sleep and personal activities. This report examines work start time differences from three different databases previously published by the Federal Railroad Administration: the Fatigue Accident Validation database, the Work Schedules and Sleep Patterns of Train and Engine Service Workers database, and the Work Schedules and Sleep Patterns of Passenger Train and Engine Service Workers database. A statistical description is provided for start time differences for Freight Train and Engine (T&E) crews on days with accidents (Accidents), Freight T&E on days preceding accidents (Pre-accident), T&E on days without accidents (T&E), and Passenger T&E on days without accidents (Passenger T&E). Start time difference unpredictability (σ2) was ordered as follows: σAccidents 2≥ σPre−accident 2> σT&E 2> σPassenger T&E. Fatigue, as measured by the Fatigue Avoidance Scheduling Tool, was significantly correlated with start time difference unpredictability. The start time difference variance and hazard function are useful statistical measures for determining start time variability and predicting fatigue in work schedules.